PERTH organisers of the screening of a controversial anti-vaccination documentary have defended their decision to keep the viewing location secret until two hours before the event.

The Australian Vaccination-Skeptics Network founder Meryl Dorey, who will appear at tonight’s screening of Vaxxed: from cover up to catastrophe, said secrecy is essential due to threats of violence aimed at attendees and venue operators.

She said these threats come from people who are pro-vaccine.

Ms Dorey said the government is currently running a “fear campaign” around the issue.

“What the government is doing right now is oppression and censorship,” she said.

“We need have a discussion about this issue.”

She said there is a small segment of the community who believe people have no right to research this issue.

“If the government wants everyone to vaccinate their children they need to prove the vaccinated are healthier than the unvaccinated,” she said.

Ms Dorey said the national childhood vaccination register has these statistics, but the government will not release them.

Vaxxed claims the Centre For Disease Control in the USA covered up evidence that autism and vaccines are linked.

In response to controversial documentary, the President of the Royal Australian College of General Practitioners has reminded doctors to keep the conversation open with patients opposed to vaccination.

Dr Frank Jones said immunisation is safe and effective at protecting children from harmful diseases.

Measles and whooping cough are serious and can be fatal,” he said.

Dr Jones said he has had confirmed whooping cough cases at his Mandurah practice this year.

“There was also a measles scare in Perth,” he said.

“Vaccines in Australia are safe and they work.”

Dr Jones said he has patients “who are vehemently opposed to vaccination no matter what evidence they’re presented”.

“They’re fixed in their outlook,” he said.

“But as doctors we need to keep the conversation going with these patients.

“The vast majority do the right thing and a small minority have an opposing point of view.”

Tonight is believed to be the second time the documentary will be publicly screened in Perth.